Buffing machine



Jan. 6, 1953 F. E. HENDRlCKsoN 2,624,158

BUFFING MACHINE z IN VEN TOR.

F. E. HENDRICKSON BUFFI'NG MACHINE Jan. 6, 1953 2 SHEETS-SHEET 2 Filed00t- 26. 1949 I N VEN TOR.

Patented Jan. 6, 1953 BUFFING MACHINE Soutlinllllgin,` Ill., assignorFrit'zj'E'. Hendrickson,

of one-fourth to' Bror Continuation of application Serial Thisapplication October 1949, Serialf,No..I23-,568

7 Claims)V (Cl. S12-141 l relates to polishing and builing machines andparticularly to' such machines provided with a polishing belt runningover a Work wheel. This application is a. continuation of my prior.co-pending application, for Polishing Machine, Ser. No. 680,455, ledJune 29, 1946, now abandoned.

One object of my invention is to provide a polishing machine comprising`a polishing belt, with improved means for starting up a newl belt. on aypartially resilient work Wheel.

Another object is to provide a polishing machine for supporting anabrasive belt on highly fiex'ible work wheels and on wheels that developsubstantial belt-supporting stabilityv onlyA when running'.

Another object is to provide an improved ma-v chine for polishingirregularlyeshaped pieces.

Another object is to provide an improved abrasive belt machine forpolishing manually sup'- ported pieces arid irregular pieces.

Another' object of my invention isV to provide a polishing machinecomprising` a polishingb'elt,v with improved means for aligning the belton the belt aligning pulleys.

Another object of my' invention is to provide a polishing machine havinga polishing belt, with improved means for adjusting the work wheel sothat thea front' side thereofA will. project proper amounts beyond thefront surfaces ofV thev adjacent aligning pulleys.

Stili'another obj ect of" my invention yis to provide a polishingmachine' comprising a polishing belt, the. belt operating over a workwheelwith manually''adji:r'stableA means for adjusting the po'-A sitionof' the Work Wheel after ythe start ofthe' belt `and of the machine; I

Other objects of myinvention will eitherbe ape paren-t from adescription of one My invention form of devicek embodying my inventionor will be set out in f.

G. Giving, Elgin, III.

Fig. 8 is a sectional view therethrough taken on the line 8-8 of Fig. 5.

the cou-rse of suc-h description andl particularly setrforth vin theappended claims.

f In the drawings, Y Figure lis a View side elevation of abeltp'olishing machine embodying myA invention;

-Fi`g.f.2 isafront elevationall viewof the-machine shown in. Fig. 1-; Y

3- is a. sectional view, on an enlarged scale, on1the-line3-3 of Fig'.l; Figvlf isa vertical sectional-view therethrough;- takenonthe-.lineA-ll of. Fig. 3; Y

Fig. 5 is a. horizontal sectional view taken. on the line. 55 of Fig/'7Fig. (i is: a diagrammatic. view showing` different. positions, of thework wheel relative to the twoi aligning pulleys;v

Fig. 'l is a fragmentary.. sectional viewY taken. on` the line ,.'|-i|Aof Fig;l 5 and,

Abrasive belts have been employed with rigid wheels, rubber facedwheels, and even sewed fabric Wheels, as for example in the so calledbackestand idler arrangement, but in such machines the work wheel wasrequired to supev port and guide the belt and so was necessarily of a rmorrigid construction even though it might have a slightly-yielding,belt-contacting face;

In laccordance with my present invention I employ a belt-backing. workwheel, or back-up Wheel, of a highly flexible segmental constructionthat develops substantial belt-supporting, stability only while running.I have found that a belt on such a wheel yields4 to the pressure of Workand folds the belt over convex protuberances` and into holloWs of thework piece'.

Further, my present invention provides a machine, and method ofoperation thereof, for starting. up a belt on such a wheel wherein theflexible work wheel is required to supportA the belt only after it hasattained a speed at which it develops suihcient belt-supportingstability.

Referring rst of all to Figs. l and 2 of the drawings, I have thereillustrated, particularly in Fig. 1 of the drawings, a view in sideelevation of a belt polishing machine designated generallyl in itsentirety by While I have. shown a polishing machine comprising a pair'of polishing belts, I do' not desire toV be limited thereto', but'an'early device of' this kind built byrne was providedA with twopolishing belts, sov that such assembly has been shown here purposes.The machine ll comprises a skeleton frame I3 consisting of verticallyextending angle bar members l5 and |1 as well as horizontal lower anglebar members |'9 and upperv angle bar' members 2| together with upper andlower horizontal cross angle bar members 23. The assembled members |57,I1', i9, 2| and 23 are suitably s`e= cured together as bywelding so 4asto provide a skeleton frame, members I5 being longer than members l1.

An electric motor 25l of suitable size and speed.

is adapted to be mounted upon the lower angle bar members I9 and 23 andVis adapted to drive by a belt 21, a driving pulley 29 mounted onra shaft3|. Shaft 3| is supported bybea'rings which are secured tothe upperangle bars 2|.

I provide furtherv an uppershaft 3l which is rotatably supported as byva plurality of bearings 3Sy andA 4| which are suitably securedr againstthe front surface off the forward vertical barsA f5 at the upper endthereof. Polishing belts` is and-45- are adapted to operate over a pairof spaced aligning pulleys 41 and l5 onzthe-righta-handside of the frameas seen in Fig. 2' andover aligning for illustrative pulleys vI and 53on the left-hand side of the frame. Pulleys 4'! and 5I are adapted to besuitably rotatably secured on shaft 3l. The lower belt aligning pulleys49 and 53 are adapted to be supported on short shafts 55 and 5'I whichare adapted to be rotatably supported by bearings 59 and 6I which areadapted to be specially mounted as will hereinafter appear.

I provide also a pair of work wheels 63 which are preferably of the kinddisclosed and claimed in my co-pending application, S. N. 657,804, filedMarch 28, 1946, to which application reference may be made for thedetails of construction of the work wheels. Generally speaking, workwheel 63 is partially resilient and is of the self- Ventilating type.Each work wheel E3 is supported on a short shaft 65 which is supportedas by a pair of ball bearings 6l and G9, these ball bearings beingmouned in a hollow tubular member 1i. Member 'II is adapted to berigidly supported on a square member 'I3 te which it may be Welded as byseams l5 of welding material. Member 'I3 is adapted to project through ahollow square member 'I'I which is supported by the front end of thehorizontal bar 2 I. Member 'I3 is adapted to be adjusted longitudinallyof its length in member 'Il' by a lever arm I9 and a pin 8l secured tomember 'I3 and is adapted to be held in any fixed position relative tomember 'Il' by a short shaft 83 having a hand wheel 85 thereon so thatwhen by means of lever arm 'I9 work wheel 63 has been pushed outwardlyas far as it is deemed Wise to push lthe same, rod 'I3 may be locked ina given position. Lever arm 'I9 is pivotally mounted at its lower end,on a plate 82 secured to bar 2 I, and a pivot pin 84. Each of the lowerbelt aligning pulleys 49 and 53, and their shafts 55 and 5l, are mountedon a substantially horizontal bar 81, the rear end of which is pivotallymounted on one of the rear vertical bars I'I, as by a pin B9. Lever arm8'! is provided with a plurality of notches 9| intermediate its ends atits upper side and a short arm 93 is pivotally mounted on one of theupper bars 2 I and is provided with a laterally projecting stud or shortshaft 95 so -that when arm 8l is moved down by a short rod 91 secured toarm 81, it may be locked in its adjusted position by short arm 93engaging one of the notches 9 I. A Vertical guide bar 59 is securedtothe outside of one of the vertical bars I5 so that arm 6l may be heldin desired operative position to provide the desired tension on thepolishing belt.

Aligningpulleys 49 and 53 may be rotatably supported as by a pair ofball bearings II and |03 which are suitably secured in a hollow member|05 which is supported by a short bar I9? which may be made ofsubstantially square shape in lateral section and be secured to member|05 as by Welding seams Hill.4 ported on a short bar member I I I as bya pin I I3, member I'l being adapted to extend substantially vertically.AThe lower end of member IIl'I has screw-threaded engagement with ashort shaft I'I5 which is rotatably supported in one of the arms 8'! andis held therein by a bearing member I I'I. A compression spring H9 islocated on shaft I I5 and abuts at one end against bearing I I'Iwhile'its other end abuts against a washer IZI, which abuts against asmall hand wheel I23 secured on shaft II5. It is obvious that turningmovement of hand wheel I23 andof shaft I l5 in one direction or anotherwill cause a change in the angle of shaft 55 and therefore of aligningwheel 49 relative to the bar 81. Y

.Extended tests on my part with machines of Arm Il is pivotally sup?this general type have shown the necessity of certain featureshereinbefore described to which further reference will now be made. Ihave found, for instance, that when using a work wheel to support apolishing belt it is extremely difficult to start up a new belt on abelt polishing machine when using a partially resilient Work Wheel, ifmore than a slight amount of pressure is exerted by the polishing beltupon the work wheel before the belt has reached its proper operatingperipheral speed. I have also found that when a new polishing belt hasbeen started by means of the method hereinbefore described, the machinecan be started and stopped any number of times for the lifetime of thebelt without readjusting the pressure of the belt on the work wheel andthat the belt Will remain aligned on the face of the Work wheel whilerunning no matter how unbalanced the pressure of the work may be or fromwhat angle the work piece to be polished may be applied to the beltsupported by the work wheel.

Although the flexible work wheel E33 is incapable of properly guidingthe belt or adequately sustaining much pressure, the aligning pulleys4'! and 49 serve to keep the belt from running off in spite of thetendency of a Work piece to deflect the belt to one side Whenever it isapplied off balance.

I have further found that in a belt-polishing machine of the type hereindescribed, it is important that the extreme front end of the work Wheelproject well beyond the front surfaces of the two adjacent alignmentwheels, in order to provide room for manipulating the work piece whileit is being polished and also to present a sufficiently large andresiliently cushioned surface for larger pieces of work.

I have particularly noticed that the machine will perform mostsatisfactorily when the in cluded angle formed by the two stretches ofthe polishing belt over the Work Wheel is between and and when thediameter of the work Wheel is approximately three to four times itsWidth. Reference may be had to Fig. 6 in regard to just What is meant by90 and 150. The sec'- tion of the Work Wheel contacted by the belt willvary between 30 as a minimum and 90 as Aa maximum.

I may here again point out that as described in my hereinbeforementioned co-pending application, the work wheel 63 is made ofrelatively soft material and is of a sectional, iiexible constructionhaving, however, some inherent stability and is preferablyV of theventilated type.` It is evident that when the machine lis not operatingthat there will be no centrifugal force actingv upon the individualsections ofA the work Wheel to tend to hold them extending substantiallyradially outwardly and to give them substantial belt-supportingstability. When starting up motor 25 and therefore the polishing belt43, I have found that it is extremely difficult to properly start up anew belt on a belt polishing machine of the kind shown in the drawingsif the work wheel has complete freedom from inherent stability asconsiderable pressure is exerted by the polishing belt upon the workwheel before the belt has reached its proper peripheral speed. Forpractical operation, I have found that the width of the periphery of thework wheel when running at full speed should be approximately the sameasthe width of the polishing belt in order to be able to reach corners andbends in the workpiece to be polishedi and that this width should befrom one-fourth to one-halfof the vdiameteiwofgthe work wheel. A narrowwheel tends to give the belt less support so that it is more easilypushed off by the unbalanced application of a work piece, whereas toowide a belt tends to double up in a longitudinal fold if a corner orpoint of the work piece is pressed deep into it. I have further foundthat when a new belt is installed and the machine has been adjusted atthe initial run by means of the novel features hereinbefore described,the machine can be started and stopped any number of times for thelifetime of the belt and the belt will remain on the work wheel whilerunning no matter how unbalanced the pressure may be that is applied bythe work piece against the belt over the work wheel.

When a new belt has been installed around the l various pulleys 29, 41,63 arm 93 disengaged from arm 81, the operating handle 19 is movedtoward the work wheel just sufliciently to lift the pulley 49 from itslowermost position, thereby causing the polishing belt 43 to exert avery slight pressure on work wheel 63. The driving motor 25 is thenstarted and the operating handle 19 is gradually moved so as to causemore pressure to be exerted by the work wheel against the polishingbelt.

While the work wheel is thus gradually moved forward manually, theoperator watches the alignment of the polishing belt upon the work wheelfrom the .front of the machine as seen in Fig. 2. If any tendency tomisalignment is observed, the adjusting wheel |23 is turned in theproper direction to bring the polishing belt in perfect alignment withthe Work wheel. As soon as such alignment has been effected, theoperating handle 19 is moved all the way forwardly and the work wheel islocked in this position by means of the locking hand wheel 85. At thisstage the only tension on the polishing belt is caused by the gravity ofpulley 49 and lever arm 81, but this tension is not sufiicient forsatisfactory operation. Manual pressure is then exerted downwardly onhandle 91 on lever arm 81 and at the same time locking lever 93 ispushed downward against the teeth 9| provided in the upper edge of leverarm 81. Considerable pressure can be obtained by this method and anexperienced operator will soon determine just what is the optimumpressure. I provide a biased take-up, or automatic control of thetension of the belt during the starting of the machine, the truing up ofthe alignment, and the setting of the work wheel; and I provide alsomeans for locking the takeup wheel in an adjusted position during theuse of the machine.

Various modifications may be made in the device embodying my inventionwithout departing from the spirit and scope thereof and all suchmodiiications coming clearly within the scope of the appended claimsshall be considered as covered thereby.

I claim: j

1. In combination in a polishing machine, a plurality of pulleys for apolishing belt comprising two aligning wheels and a work wheeltherebetween, said work wheel comprising a hub and a plurality ofseparate segmental outward-extending sections of flexible materialsupported thereon, the whole wheel being so flexible that it develops asubstantial part of its belt-supporting stability by centrifugal-force,a movable support for said work wheel permitting movement thereoftransverse the tangent between said aligning wheels sufficient to movesaid work wheel from a position in which it barely touches a and 49, andwith lever belt on said aligning wheels to a position in which from 30to 90 angular degrees of the periphery of an uncompressed work wheelengages said belt, another of said plurality of pulleys having a movablesupport movable for tightening a belt, and means for locking the movablesupports of said work wheel and belt-tightening pulley.

2. The combination of the immediately preceding claim wherein saidbelt-tightening pulley includes means for biasing it in abelt-tightening direction.

3. A polishing machine as set forth in claim 1 in which the diameter ofthe work wheel is from two to four times the Width of its face.

4. The combination of claim 1 wherein there is included a belt on saidpulleys having a width substantially equal to the width of the workwheel.

5. In a polishing machine including a, pulley stand, the combinationwith a driving pulley for an abrasive belt and a support for the drivingpulley, of, a supporting structure forward of the drive pulley, twoforwardly-projecting pulleysupporting brackets thereon for supportingtwo aligning pulleys one substantially above the other, aligning pulleyson said brackets in position to receive and guide an abrasive belt,means for adjusting one of said brackets about an axis at an angle tothe axes of said three pulleys for changing the angularity of itspulley, means for adjusting one of said brackets in a direction toaifect the tension of a belt on said pulleys, a work wheel for backingup said belt mounted on said supporting structure between said twoaligning pulleys, and means for adjusting the work wheel against thebelt for deflecting it from a straight path between said two aligningpulleys.

6. The combination of claim 5 wherein the one of said brackets isadjustable for imposing both said adjustments on the wheel thereon.

7. The method of backing a polishing belt in a polishing machine whereinthe belt travels over supporting pulleys and a soft backing pulleyhaving belt supporting stability only when rotated, which methodcomprises starting the belt running over the pulleys but in only lightcontact with the backing pulley whereby to start the backing pulleyrotating, then moving the backing pulley into iirmer contact with thebelt to increase the speed of rotation of the backing pulley andsupporting the belt under working tension against the belt supportingface of the soft backing pulley when it is rotating substantially at thesurface speed of the belt.

FRITZ E. HENDRICKSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 314,906 Young Mar. 31, 18851,045,945 Carney Dec. 3, 1912 1,744,807 Schulte Jan. 28, 1930 1,754,292Warren Apr. 15, 1930 2,280,399 Garling Apr. 21, 1942 2,334,960 Roth etal Nov. 23, 1943 2,376,847 Glike May 22, 1945 2,402,131 Fowler June 18,1946 2,415,947 Hendrickson Feb. 18, 1947 2,431,795 Elmes Dec. 2, 19472,469,735 Lindsay et al May 10, 1949

